On Wed, 14 Jun 2006, Kai Lin Woon wrote:
I might have a suggestion that might sound stupid. I am looking at photonic crystal slab. I am trying to reproduce the light cone. The light cone is bounded by w=ck/n. In a TMKT band diagram, the n is the average refractive index at a given direction. However, in the paper
The light cone is *not* determined by the "average" refractive index in a given direction, at least not for any simple definition of "average". Rather, it is determined by the lowest-lying mode of the cladding as described in the PRB paper that you mention.
For a homogeneous cladding, of course, this is just w=ck/n. But for a periodic cladding, say oxide pierced by a 2d array of holes, then to get the light line you must do a 2d calculation of the band structure in the oxide pattern...the lowest (TM *or* TE) band of this 2d pattern is then the boundary of the light cone.
Cordially, Steven G. Johnson _______________________________________________ mpb-discuss mailing list mpb-discuss@ab-initio.mit.edu http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/mpb-discuss
